A strong cable (usually polybuckminsterfullerene or some semi-elastic diamondoid) lowered from a geosynchronous satellite and anchored to the ground, often with a counterweight at the outer end to provide some extra tension and stability. It provides cheap and simple access to space using elevators. Most developed worlds have a series of beanstalks connecting the surface with orbitals. Although the effect from a beanstalk breaking and whiplashing around the planet would be quite serious, this has only rarely happened.
Polyfullene - Text by Anders Sandberg Polybuckminsterfullerene; nanofactured fullerene composite produced originally for Beanstalks but which also found many uses elsewhere. Polyfullene has a tensile strength close to the theoretical limits of molecular matter; a single one millimeter strand can easily support many tons. The most impressive property is that it is self-healing: if the nanotubes inside a Polyful filament are broken, fullerene from the matrix heals them only causing a slight lengthening.